Highly sensitive detection of the group A Rotavirus using Apolipoprotein H-coated ELISA plates compared to quantitative real-time PCR

<p>Abstract</p> <p>Background</p> <p>The principle of a capture ELISA is binding of specific capture antibodies (polyclonal or monoclonal) to the surface of a suitable 96 well plate. These immobilized antibodies are capable of specifically binding a virus present in a clinical sample. Subsequently, the captured virus is detected using a specific detection antibody. The drawback of this method is that a capture ELISA can only function for a single virus captured by the primary antibody. Human Apolipoprotein H (ApoH) or β₂-glycoprotein 1 is able to poly-specifically bind viral pathogens. Replacing specific capture antibodies by ApoH should allow poly-specific capture of different viruses that subsequently could be revealed using specific detection antibodies. Thus, using a single capture ELISA format different viruses could be analysed depending on the detection antibody that is applied. In order to demonstrate that this is a valid approach we show detection of group A rotaviruses from stool samples as a proof of principle for a new method of capture ELISA that should also be applicable to other viruses.</p> <p>Results</p> <p>Stool samples of different circulating common human and potentially zoonotic group A rotavirus strains, which were pretested in commercial EIAs and genotyped by PCR, were tested in parallel in an ApoH-ELISA set-up and by quantitative real-time PCR (qPCR). Several control samples were included in the analysis. The ApoH-ELISA was suitable for the capture of rotavirus-particles and the detection down to 1,000 infectious units (TCID_50/ml). Subsets of diagnostic samples of different G- and P-types were tested positive in the ApoH-ELISA in different dilutions. Compared to the qPCR results, the analysis showed high sensitivity, specificity and low cross-reactivity for the ApoH-ELISA, which was confirmed in receiver operating characteristics (ROC) analysis.</p> <p>Conclusions</p> <p>In this study the development of a highly sensitive and specific capture ELISA was demonstrated by combining a poly-specific ApoH capture step with specific detection antibodies using group A rotaviruses as an example.</p

Re-assessing the total burden of norovirus circulating in the United Kingdom population

The second Infectious Intestinal Diseases study (IID2) estimated the incidence of norovirus in the UK at 47/1000 population (three million cases annually). Clinically significant norovirus was defined using a cycle threshold (ct) value of <30; a more stringent cut-off than used in diagnostic laboratories. The low infectious dose of norovirus means asymptomatic individuals potentially contribute to ongoing transmission. Using a less stringent but diagnostically relevant threshold increases the estimation of the population burden of norovirus infection by around 26% to 59/1000 person years (95% CI 52.32–64.98), equating to 3.7 million norovirus infections annually (3.3–4.1 million). With possible vaccines on the horizon for norovirus, having a good estimate of the total burden of norovirus infection, as well as symptomatic disease will be useful in helping to guide vaccination policy when candidate vaccines become available

Age-Specific Incidence Rates for Norovirus in the Community and Presenting to Primary Healthcare Facilities in the United Kingdom.

In a prospective, population-based cohort study and a study of primary-healthcare consultations, we had a rare opportunity to estimate age-specific rates of norovirus-associated infectious intestinal disease in the United Kingdom. Rates in children age

Ecological assessment of the direct and indirect effects of routine rotavirus vaccination in Merseyside, UK using data from multiple health systems: a study protocol

INTRODUCTION: Rotavirus is the most common cause of severe gastroenteritis in infants and young children worldwide. Currently 67 countries include rotavirus vaccine in childhood immunisation programmes, but uptake in Western Europe has been slow. In July 2013, rotavirus vaccine was introduced into the UK's routine childhood immunisation programme. Prior to vaccine introduction in the UK, rotavirus was estimated to result in 750 000 diarrhoea episodes and 80 000 general practice (GP) consultations each year, together with 45% and 20% of hospital admissions and emergency department attendances for acute gastroenteritis, in children under 5 years of age. This paper describes a protocol for an ecological study that will assess rotavirus vaccine impact in the UK, to inform rotavirus immunisation policy in the UK and in other Western European countries. METHODS AND ANALYSIS: In Merseyside, UK, we will conduct an ecological study using a ‘before and after’ approach to examine changes in gastroenteritis and rotavirus incidence following the introduction of rotavirus vaccination. Data will be collected on mortality, hospital admissions, nosocomial infection, emergency department attendances, GP consultations and community health consultations to capture all healthcare providers in the region. We will assess both the direct and indirect effects of the vaccine on the study population. Comparisons of outcome indicator rates will be made in relation to vaccine uptake and socioeconomic status. ETHICS AND DISSEMINATION: The study has been approved by NHS Research Ethics Committee, South Central-Berkshire REC Reference: 14/SC/1140. Study outputs will be disseminated through scientific conferences and peer-reviewed publications. The study will demonstrate the impact of rotavirus vaccination on the burden of disease from a complete health system perspective. It will identify key areas that require improved data collection tools to maximise the usefulness of this surveillance approach and will provide a template for vaccine evaluations using ecological methods in the UK

Genetic diversity of porcine group A rotavirus strains in the UK

Rotavirus is endemic in pig farms where it causes a loss in production. This study is the first to characterise porcine rotavirus circulating in UK pigs. Samples from diarrheic pigs with rotavirus enteritis obtained between 2010 and 2012 were genotyped in order to determine the diversity of group A rotavirus (GARV) in UK pigs. A wide range of rotavirus genotypes were identified in UK pigs: six G types (VP7); G2, G3, G4, G5, G9 and G11 and six P types (VP4); P[6], P[7], P[8], P[13], P[23], and P[32]. With the exception of a single P[8] isolate, there was less than 95% nucleotide identity between sequences from this study and any available rotavirus sequences. The G9 and P[6] genotypes are capable of infecting both humans and pigs, but showed no species cross-over within the UK as they were shown to be genetically distinct, which suggested zoonotic transmission is rare within the UK. We identified the P[8] genotype in one isolate, this genotype is almost exclusively found in humans. The P[8] was linked to a human Irish rotavirus isolate in the same year. The discovery of human genotype P[8] rotavirus in a UK pig confirms this common human genotype can infect pigs and also highlights the necessity of surveillance of porcine rotavirus genotypes to safeguard human as well as porcine health

Rotavirus vaccine impact and socioeconomic deprivation: an interrupted time-series analysis of gastrointestinal disease outcomes across primary and secondary care in the UK.

Background Rotavirus causes severe gastroenteritis in infants and young children worldwide. The UK introduced the monovalent rotavirus vaccine (Rotarix®) in July 2013. Vaccination is free of charge to parents, with two doses delivered at 8 and 12 weeks of age. We evaluated vaccine impact across a health system in relation to socioeconomic deprivation. Methods We used interrupted time-series analyses to assess changes in monthly health-care attendances in Merseyside, UK, for all ages, from July 2013 to June 2016, compared to predicted counterfactual attendances without vaccination spanning 3–11 years pre-vaccine. Outcome measures included laboratory-confirmed rotavirus gastroenteritis (RVGE) hospitalisations, acute gastroenteritis (AGE) hospitalisations, emergency department (ED) attendances for gastrointestinal conditions and consultations for infectious gastroenteritis at community walk-in centres (WIC) and general practices (GP). All analyses were stratified by age. Hospitalisations were additionally stratified by vaccine uptake and small-area-level socioeconomic deprivation. Results The uptake of the first and second doses of rotavirus vaccine was 91.4% (29,108/31,836) and 86.7% (27,594/31,836), respectively. Among children aged < 5 years, the incidence of gastrointestinal disease decreased across all outcomes post-vaccine introduction: 80% (95% confidence interval [CI] 70–87%; p < 0.001) for RVGE hospitalisation, 44% (95% CI 35–53%; p < 0.001) for AGE hospitalisations, 23% (95% CI 11–33%; p < 0.001) for ED, 32% (95% CI 7–50%; p = 0.02) for WIC and 13% (95% CI -3–26%; p = 0.10) for GP. The impact was greatest during the rotavirus season and for vaccine-eligible age groups. In adults aged 65+ years, AGE hospitalisations fell by 25% (95% CI 19–30%; p < 0.001). The pre-vaccine risk of AGE hospitalisation was highest in the most socioeconomically deprived communities (adjusted incident rate ratio 1.57; 95% CI 1.51–1.64; p < 0.001), as was the risk for non-vaccination (adjusted risk ratio 1.54; 95% CI 1.34–1.75; p < 0.001). The rate of AGE hospitalisations averted per 1,000 first doses of vaccine was higher among infants in the most deprived communities compared to the least deprived in 2014/15 (28; 95% CI 25–31 vs. 15; 95% CI 12–17) and in 2015/16 (26; 95% CI 23–30 vs. 13; 95% CI 11–16). Conclusions Following the introduction of rotavirus vaccination, incidence of gastrointestinal disease reduced across the health-care system. Vaccine impact was greatest among the most deprived populations, despite lower vaccine uptake. Prioritising vaccine uptake in socioeconomically deprived communities should give the greatest health benefit in terms of population disease burden

A is for Anthropocene:An A–Z of Design Ecology

This paper lists in A to Z format the changing ecology of design in the Anthropocene. From twenty-six points of view the paper contrasts design’s search for a coherent ecology – how it looks like it looks – with its search for a familiar ecology – how it is understood today. Taking each letter of the alphabet to create individual reviews of the vicissitudes of design, the paper critiques how design has historically explained to itself, and anyone who has been listening, what it has been doing, and contrasts that with what needs to be done